On 23 July, exactly 1 month after Britain's momentous decision to leave the European Union, around 4500 scientists and friends of science will assemble in Manchester, UK, for the opening of the EuroScience Open Forum (ESOF), Europe's largest interdisciplinary research conference. The vote for Britain's exit (“Brexit”)—with worrying repercussions for European science and wider society—and questions about the plans of the new UK Prime Minister Theresa May, will inevitably cast a shadow over proceedings. But as Jerzy Langer, chair of ESOF's program committee, argues, the meeting has now acquired a sharper purpose: to demonstrate at a time of acute uncertainty that “we, the scientists, are one big family, whose rules and values extend beyond political and geographic borders.”

Concern about the implications of Brexit for science has focused primarily on the obstacles it may pose to continued collaboration and free movement of researchers across Europe. However, the dense web of connections between British and European science extends into many other areas, including science policy and the provision of evidence and expert advice to decision-makers.

One example is the European Commission's Scientific Advice Mechanism (SAM), announced last year by Carlos Moedas, the Commissioner for Research, Science and Innovation. After an open nomination process, a high-level group of seven advisers was appointed and began its work in January 2016. Supported by a Brussels secretariat, the SAM will also procure advice from networks of national academies and learned societies across Europe.

The SAM's first two projects—on CO2 emissions from light-duty vehicles; and digital identities and cybersecurity—are well advanced, and on target to release findings before the end of 2016. It also recently published an explanatory note on the safety and risks of the herbicide glyphosate, which remains a vexed issue in Europe.

Henrik Wegener, inaugural chair of the SAM's high-level group, has emphasized the need for it to work in an independent, transparent, and consultative way. In support of this goal, its next meeting will take place at ESOF, providing a first opportunity for the wider research community to engage with the SAM's work. A summit meeting this September of the International Network for Government Science Advice will be hosted in Brussels by the European Commission, at which the SAM will play a prominent role.

These are still early days for the SAM. It has met just twice, and its initial priorities were proposed by Brussels policy-makers. It is envisaged that the SAM will soon begin to work in both reactive and proactive ways, and the high-level group has developed a long list of potential topics and questions where it could make a meaningful contribution to European Union (EU) decision-making. How it strikes a balance between independence and policy relevance, and how far it gets drawn into the more contested terrain between evidence, policy, and politics, remain to be seen.

Even before Brexit, the ESOF meeting intended a strong focus on science policy. In the present climate, this is more important than ever. The vocal dismissal of evidence and expertise during what some described as the UK's “post-fact” referendum on the EU raises the possibility of a reversal of progress toward more evidence-informed decision-making. There is a risk that such a trend will spread to other fields and become more prominent in European political discourse, and that the research community will adopt overly defensive or dismissive positions.

Argument and analysis of events over the past month will be prominent at ESOF, but answers are likely to require a more searching period of reflection. Hopefully, the SAM can provide one arena through which these debates move forward within Britain, across Europe, and beyond.